YOU SAID:
I cant believe that my manager is dumb
INTO JAPANESE
私のマネージャーが愚かだとは信じられない
BACK INTO ENGLISH
I can't believe my manager is stupid
INTO JAPANESE
マネージャーがバカだとは信じられない
BACK INTO ENGLISH
I can't believe the manager is stupid
INTO JAPANESE
マネージャーがバカだとは信じられない
BACK INTO ENGLISH
I can't believe the manager is stupid
That didn't even make that much sense in English.